The invention relates to a cantilever-type structure for supporting a vacuum hose or other duct. Such apparatus may be used, for example, in the grain handling field to support a hose used to convey grain from a storage facility to the plenum of a grain vacuum conveyor and which is operated by an operator carrying an end of the hose by hand to manipulate and guide the hose intake.
A variety of applications require an operator to manipulate a lengthy, heavy flexible duct or hose. In the grain handling field, hoses are typically used to convey grain by vacuum to the plenum of a vacuum conveyor, from where it is typically transported by auger or other transport means to a storage bin, truck or elsewhere. Typically, such hoses are lengthy and heavy in order to handle a large volume of grain, and are correspondingly awkward to use. Some of the weight may be borne by a harness worn by the user. However, unless a support means is employed to take up at least a portion of the weight, the weight of the duct or hose is still quite heavy. For use with a flexible duct, for example in the grain handling field, such a support must accommodate the side-to-side movement requirements of the user. In most such applications, the duct must span a relatively large horizontal distance and be capable of accommodating a large sweeping movement. However, such applications typically require only limited vertical travel of the duct. Preferably, the duct should be suspended in a generally vertical orientation such that it is elevated for substantially its entire length, with the free end of the duct depending downwardly for manipulation by the operator.
It is known to provide a support apparatus for various duct and conveyor configurations. For example, U.S. Pat. No. 3,690,731 (Mylting) and U.S. Pat. No. 3,382,011 (Mascarello et al.) disclose a flexible vacuum tube supported by a moveable boom. U.S. Pat. No. 5,322,393 (Lundquist) discloses flexible tube for use in an ore unloading apparatus, supported by a swingable horizontal boom, with a cable at end of the boom supporting the hose. The prior art supports are not well suited for applications where a relatively heavy duct must be elevated above the ground and supported over a relatively long horizontal distance, while permitting an operator to manipulate the duct in sweeping and serpentine movements. The capability to accommodate these movements is necessary in order to permit the operator to position an intake end of the duct over any desired spot over a surface, for example where the operator is vacuuming up grain distributed broadly over a surface.
In a typical grain vacuum duct application, the support must permit a large degree of side to side and back and forth mobility to the user. For this purpose, a boom-type support may be used to suspend the duct over substantially the length of the duct, with the support having the ability to flex, bend or fold in a generally horizontal plane to provide both sweeping and serpentine movement to the duct. This may be accomplished by means of articulations in the support structure that permit horizontal flex but limited vertical travel, since in the vertical plane the support must be able to support the heavy weight of a thick-walled, large diameter duct loaded with grain.
One problem that must be overcome in a hose support used for this purpose, is that a support that has the desired flexibility tends to collapse when bearing a heavy duct. This is particularly the case with a relatively long articulated support structure. Accordingly, it is desirable to provide a support having means to prevent collapse when supporting a duct for the transport of grain or other heavy material, while still capable of sweeping movement.
It is further desirable to provide a hose support that is foldable or collapsible. This feature permits the equipment to collapse into a compact unit for transport or storage.
A further desirable feature is to allow for changing the overall length of the support with relative ease to accommodate different conveying lengths. This may be accomplished with a modular arrangement whereby individual sections may be added or deleted.
Articulated and foldable supports of the prior art exist for a variety of applications. For example, U.S. Pat. No. 4,640,062 (Rubik) discloses an articulated support. Several references disclose holding arm arrangements for supporting various objects such as computer or video terminals, including U.S. Pat. No. 4,695,024 (Haven); U.S. Pat. No. 4,836,486 (Vossoughi et al.), U.S. Pat. No. 3,550,892 (Prepst). These types of supports permit the operator to position the screen in virtually any desired location within the reach of the support. However, these types of supports are not without modification capable of supporting a heavy load.
It is an object of the present invention to provide a support means, and in particular a folding support means, for supporting a flexible duct or hose. It is a further object to provide a support capable of providing horizontal support to elevate above the ground a relatively heavy duct over a relatively long span, while permitting horizontal sweeping and serpentine movement of the duct. It is a further object to provide a duct support foldable or collapsible for storage. It is a further object to provide a modular support capable of accommodating different conveying lengths.
In order to achieve the strength and rigidity required for this application, the support may conveniently comprise rectangular panels that are hinged together in a linear array. For weight reduction, the panels may comprise open truss arrangements.
It has been found that a boom type support comprised of a linear array of panels hinged together is capable of supporting a relatively lengthy and heavy duct, if the support features a gentle upward curve from its base to its end. When the duct is suspended from the support, the upward curve biases the support upwards, counteracting the weight of the loaded duct and lowering the risk of collapse of the support.
In its broadest aspect, the present invention comprises a boom type support arm for carrying an elongate flexible duct, of the type comprising an elongate structure having a proximate end for mounting to a base and a distal end, with attachment means to attaching a duct to the arm. The invention is characterized by the support arm comprising a linear array of rigid panels hingedly joined together. The hinges permit the panels to fold in on themselves such that adjacent panels may lie generally parallel to each other when folded, while permitting lateral flexibility of the support when the support is unfolded for use. When extended, the array curves slightly upwardly from the first to the second ends. The upward curve of the array may be provided by canted hinges that tilt successive panels upwardly. Preferably, the panels comprise truss panels. A duct or hose may be carried by means of slings or other attachment means that suspend the duct or hose from the support.
The individual panels are conveniently all identical in size and shape for ease of assembly. It will be seen, however, that non-identical panels may be employed.
A further convenient feature is of the use of hinges that permit the rapid attachment or detachment of individual panels. Conveniently, this may be provided by means of an eyelet and pin arrangement, whereby each panel is provided with eyelets positioned to mate with the eyelets of a neighbouring panel, and a removable pivot pin insertable through the eyelets releasably and pivotally joins the panels.
The invention further comprises the combination of a duct support as characterized above and a flexible duct or hose.
While conveniently the duct is suspended from the support, the invention is not limited to suspensive support and the support may be adapted to carry a duct by other means.
The invention will now be described by way of a preferred embodiment. It will be understood that the terms xe2x80x9chorizontalxe2x80x9d and xe2x80x9cverticalxe2x80x9d as used herein refer to the support in its ordinary, generally horizontal orientation. It will be understood that the support may be tilted away from the horizontal, and the directional references herein shall not be construed as limitative in this respect.